Process Color
Introduction
Continuous-tone artwork in full color and intended for reproduction is better
left to the camera person for photographic separation. Better reproductions
result from using colors in the original that are similar to the colors of ink the
printer uses. Master the processes used in preparing continuous-tone
originals for color reproduction.
Color
The two categories of color reproduction methods are process color and flat
reproduction
color.
Process color
Process color is the four-color separation and printing process of continuous-
tone masters requiring photographic separation of each of the three primaries
plus black. The three primary process colors are cyan (blue) abbreviated
(C), yellow abbreviated (Y), magenta (red) abbreviated (M). The three
primary process colors plus black (K) are the foundation of the CYMK
process color theory. The CYMK process color theory uses inks to
reproduce color images. Each isolated. color creates a plate which, when
printed in turn, reproduces the original in full color.
How process
color works
The printer makes separate negatives and separate press plates for each of the
primary colors plus black (a total of four) in continuous-tone color art. The
camera person may use only three negatives and three plates if the artwork is
simple. Since colors photograph as black or shades of grey, the printer uses
regular black-and-white panchromatic litho film. A grey scale, photographed
along side the artwork assists the camera person in comparing density and
contrast for each negative. Negatives should have the same density and
contrast or they print out of balance. The photographer uses halftone screens
and color filters when shooting color separations. The halftone screen breaks
the image into dot patterns. The angle of the halftone screen changes for
each color shot. This change in angular position causes the film to record
dots that, when printed, overlap. A blue filter records yellow, a red filter
records cyan (blue), and a green filter records magenta (red). No filter or a
combination of the three filters records black in the original. The filters used
by the camera person are not true blue, red, and green. Filters have
numerical values based on density and color.
Select the filter with the
correct numerical value to achieve maximum contrast and density.
Overlapping differently colored dots creates secondary and tertiary colors.
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